Chewing gums are conventionally prepared from ingredients including sugar, gum base, corn syrup, color and flavoring. The gum base is typically heated and combined while hot with the other ingredients in a suitable mixer, with or without the addition of supplemental agents which produce desired modifications of texture, chewing characteristics and the like. The material discharged from the mixing vessel is a tough, taffy or dough-like mass which is passed through rolls and sheeting and scoring machines, or extruded, sized and cut, in accordance with practices well known in the art, to produce the final chewing gum product.
The final chewing gum product described above normally contains about 3-5% by weight of moisture. It is believed that due to a synergistic effect of combining liquid sugar and corn syrup with gum base, these products may result in having a bitter flavor or taste.
Over the years, there have also been developed a variety of processes for producing chewing gum which is light weight and low in specific gravity and which gives a soft chewing sensation when chewed. One such method involves mixing foaming agents with the chewing gum composition in the presence of water, and heating the mixture to a temperature in the range of from 110.degree. C. to 160.degree. C. This method also tends to harm the desired flavor and taste of the chewing gum products. In another method for preparing aerated chewing gum, a foaming agent and a gelatin are mixed with chewing gum base which has been foamed. The disadvantage of using foaming agents and gelatin is the inability to obtain a chewing gum product having good flavor and taste. Another disadvantage with processes which involve the use of foaming agents is that in order to obtain an aerated candy gum having desirable homogeneous texture, the degree of foaming must be accurately controlled by maintaining operating conditions, such as temperature, etc., at a precise level, which, as a result, renders quality control difficult.
A still further method of preparing a low density chewing gum product comprises formulating a chewing gum composition into a liquid batch, whipping the batch (preferably under an inert atmosphere) to gassify it, pouring the gassified mass into molds of a predetermined shape, subjecting the gassified mass while in the mold to vacuum to expand the gassified mass to conform to the shape of the mold and maintaining the vacuum (typically for about 24 hours) until the expanded gassified batch in the mold becomes shape-retaining at ambient conditions of temperature and pressure. A particular disadvantage of this method is the length of time which the gassified mass in the mold must be subjected to vacuum to obtain a shape-retaining product. As mentioned above, the vacuum must be maintained for approximately 24 hours to obtain the desired product. Another disadvantage is the need for special equipment to carry out gasification under an inert atmosphere in order to reduce the amount of oxidative deterioration. These disadvantages, and indeed diseconomies, weigh against production of such aerated chewing gum products on a commerical scale.